1. Field of the Invention
This invention relates to receptacles or bags for receiving urine expelled from a person using a medical urine collection device. Such devices may include urinary catheters, Foley catheters, supra pubic catheters, external incontinence devices and others. Urine expelled by the user through these types of devices is accumulated in a urine collection bag such as a “leg bag”.
2. Description of Related Art
The configuration of many conventional urine collection bags gives rise to a problem referred to as the “Siphon Effect”. The Siphon Effect refers to a phenomenon whereby negative pressure accumulates in the urinary drainage tubing and urine collection bag as urine descends through the drainage tubing. As expelled urine drops into the urine collection bag, negative pressure accumulates behind the column of urine, causing a partial vacuum in the tubing. In the case of external catheters, the vacuum tends to draw external genitor-urinary tissue toward the proximal end of the drainage tubing, at times causing pain due to skin irritation, swelling and suction force injuries of the genitor urinary tissue. Excessive wear or premature detachment of external catheters may also result from the suction caused by the Siphon Effect.
In the case of indwelling catheter users, the vacuum forces generated by the Siphon Effect impinge on the inner surface of the bladder by drawing bladder vesicle neck tissue into the drainage port of the indwelling catheter, resulting in vesicle neck irritation. Vesicle neck irritation may enhance bacterial colonization of the bladder, increasing the risk of urinary-catheter-associated urinary tract infections.
Another problem caused by negative pressure in the urine collection bag is referred to as the “Urine Backup Phenomenon”. As described above, as urine descends through the tubing to the collection bag, negative pressure is generated within the tube and within the collection bag. Many urine collection bags are constructed with an anti-reflux valve through which the urine must pass. As the urine drops through the anti-reflux valve and into the collection bag, the anti-reflux valve prevents equalization of the pressure differential between the drainage tubing and the bag. Since the collection bag may hold fifty times the volume of the tubing, the pressure differential increases considerably. This relatively large differential can cause the anti-reflux valve to remain closed, requiring greater force for the urine to exit the tubing when passing through the anti-reflux valve. Due to this increase in negative pressure within the collection bag, urine “backs up” in drainage tubing above the anti-reflux valve. This backup of urine may cause urine reflux into the urine collection device, and may push urine into contact with the user, creating the above stated problems associated with urine reflux.
Kay et al. (U.S. App. Pub. No. US 2006/0079854 A1) propose to alleviate the Siphon Effect and the Urine Backup Phenomenon primarily by eliminating the intermediate tubing between the urinary collection device and the collection bag. Unfortunately, this solution also inhibits the location of the collection bag. Kay et al also suggest that a “vent” can be used to allow ingress of air into the collection bag to equilibrate the pressure of the surrounding atmosphere and the pressure within the bag. “Vents” of this nature are known in the art.
Applicant has personally experienced pain, which he attributes to the so-called Siphon Effect, while using Foley catheters and suprapubic catheters. Applicant noticed that the pain was greater when he used an “unvented” leg bag than when he used a “vented” bedside bag. On at least one occasion, applicant heard an audible suction noise upon releasing the partial vacuum within the bag. This was accompanied by an immediate alleviation of pressure and pain.
As noted above, vented urine collection bags are known in the art. The vents disclosed generally comprise an air-permeable pad with randomly oriented fibers. When dry, the vent allows air to migrate into the collection bag. This equilibrates pressure inside and outside the bag, preventing the Siphon Effect from causing pain.
Unfortunately, vents are rarely used in leg bags. This is probably attributable to the fact that the vents cease to function as intended once they become wet, such as often occurs when the collection bag is strapped to a patient's leg. Vents of the type described can also cease to function as intended after they are washed using a vinegar solution.
Another factor that may contribute to the vacuum problem in such appliances is the effect of the weight of accumulated urine on the way in which the collection bag expands from an empty collapsed condition to an enlarged condition as urine is received from the collection device. As urine collects, the interior volume of the bag develops a urine component in the lower portion of the bag, but the upper portion of the bag remains in a collapsed condition. The urine component assumes a bulged out condition due to hydrostatic forces and the lower portion of the bag expands accordingly.
On the other hand, the volume of the upper portion of the bag does not increase significantly as urine collects in the lower portion of the bag. The result is that the upper portion of the bag is somewhat “curved” due to the weight of the urine and the walls of the upper portion of the bag are urged outwardly to try to accommodate the increased width of the expanded lower portion of the bag. The resulting forces acting to increase the width of the upper portion of the bag tend to create a partial vacuum, which may cause discomfort.
The collection bag of the present invention reduces the difficulties described above and affords other features and advantages heretofore not obtainable.